Control device for the work feeding mechanism of a sewing machine

ABSTRACT

A control device for the work feeding mechanism of a sewing machine in which any one of three separate linkages may selectively be coupled to the feed regulating means of the sewing machine. The three linkages, for manual feed control, pattern cam influence of work feed, and automatic group stitching such as buttonholing, while organized in a compact subassembly are distinct and individually tailored each to satisfy its own special requirements.

United States Patent Rogers et a1.

[54] CONTROL DEVICE FOR THE WORK FEEDING MECHANISM OF A SEWING MACHINE[72] Inventors: Frederick Rogers, Union, N.J.; Robert Bradus, Brooklyn,N.Y.; Joseph J. Winar, Roselle, NJ.

[73] Assignee: The Singer Company, New York, NY.

[22] Filed: Aug. 24, 1970 [21] Appl. No.: 66,329

[52] U.S.Cl ..ll2/2l0 [51] Int. Cl. ....D05b 27/00 [58] Field of Search..1 12/210, 158

[56] References Cited UNITED STATES PATENTS 3,339,509 9/1967 Smith..112/210 [451 Jan. 25, 1972 3,426,712 2/1969 Hanyu et al ..l12/210Primary ExaminerPatrick D. Lawson Att0rneyMarshall J. Breen, Chester A.Williams, Jr. and

Robert E. Smith [57] ABSTRACT A control device for the work feedingmechanism ofa sewing machine in which any one of three separate linkagesmay selectively be coupled to the feed regulating means of the sewingmachine. The three linkages, for manual feed control, pattern caminfluence of work feed, and automatic group stitching such asbuttonholing, while organized in a compact subassembly are distinct andindividually tailored each to satisfy its own special requirements.

5 Claims, 10 Drawing Figures PATENTEnJmzslsrz 3.636.900

SHEEI 1 0F 6 Fig. I

I mvsmons |-2 Frederick Rogers,

[ BY Robert Brclqus and Joseph J. Wmor WITNESS: I IQI- M/ #5150 JAM/$I'll/1m W ORNEY PATENTEU JAMES 1872 SHEET 2 BF 6 INVENTORS FrederlckRogers,

Robert Bro dus and Joseph J. Wmcr W 3| ATT RNEY WITNESS ed; 5% mmsmznmzsmz 3536300 56 INVENTORS Fredenck Rogers,

BY Robert Brod us and Joseph J. Wmcr ATTO NEY PATENTED M25872 SHEET b 0F6 INVENTORS Frederlck Rogers,

Robert Brodus and Joseph J. Wmor WITNESS: Weld" JAw/sg- X vw/u/rrz,

mzmenmzswzz; 3536.900

SHEET 5 0F 6 Fig.9

INVENTORS Frederick Rogers,

Y Robert Broqus and Joseph J. Wmor wnmsss; 43 a awn MMW $210M W 7 ATTONEY PATENYED JANZS I272 SHEET 8 BF 6 Frederick Rogers,

0 n 0 m w Y m E HYM 0 MM. T e T b8 00 A Rd Fig. IQ BY CONTROL DEVICE FORTHE WORK FEEDING MECHANISM OF A SEWING MACHINE BACKGROUND OF THEINVENTION When fabricating stitched buttonholes using a general purposesewing machine, as distinguished from a special purpose machine designedonly to sew buttonholes, it is necessary that the sewing machine workfeeding mechanism be regulated in a predetermined sequence of settingsto feed forwardly and then rearwardly for the production of the closedbuttonhole-shaped tack. Along with such work feed mechanism control, thezigzag mechanism of the sewing machine must also be changed in asequence of settings to provide the desired appearance of the stitchgroup.

In those sewing machines having only manual control for the feedingmechanism, buttonholing units are known which require a switching meansfor rendering either the manual control or the buttonholing control uniteffective to regulate the feed. The U.S. patent application Ser. No.739,051, filed June 21, 1968, now abandoned, Blackwood et al.exemplifies this type of feed mechanism control for buttonholing.

1n those sewing machines equipped with pattern cam control of the workfeeding mechanism effective during ordinary zigzag stitching, it isknown to provide a special pattern cam for control of the work feedingmechanism during the formation of buttonholes. The US. patentapplication Ser. No. 827,867, filed May 26, I969, Marsh et al. now U.S.Pat. No. 3,585,876, exemplifies this type of feed mechanism control forbuttonholing. Where pattern cam control of the work feed mechanism isprovided, a switching means is required for selecting manual or patterncam control of the feed mechanism.

An advantage of a buttonhole mechanism which makes use of a camcontrolled feed mechanism, when such is included in the sewing machine,is the economy gained by use of the cam controlled feed mechanism fortwo purposes. A disadvantage of such arrangement is that the feed cammechanism must then be designed and manufactured with capacity forsatisfying both of the widely differing requirements of decorativestitch patterns and of buttonholes. In decorative stitch patterns theneed is for rapid changes over a wide range of stitch lengths, while inbuttonholing only very small stitch lengths are used and the need is foruniform stitch length in forward and reverse direction.

SUMMARY OF THE INVENTION This invention provides a novel controlarrangement for the work feeding mechanism of a sewing machine in whichthree different regulators for the stitch length and direction of feedmay be selectively brought into operative relation to the work feedingmechanism. An operator influenced control such as a dial is providedwhich over a first range of positions connects a first regulator to thework feeding mechanism by which the stitch length and direction may beselected manually. Over a second range of positions of the control dialthe work feeding mechanism is connected to a second regulator which isinfluenced by a pattern cam driven by the sewing machine so thatcontinuous lines of decorative stitches may be formed in which thestitch lengths and directions vary in accordance with predeterminedpatterns. Over a third range of positions of the control dial a thirdregulator is connected to the work feeding mechanism for producingclosed stitch tacks such as buttonholes. The third work feed mechanismregulator is influenced by a cam means which is distinct from the stitchpattern cams which cooperate with the second feed regulator and thus thebuttonhole influencing cam mechanism may be tailored exclusively forperforming this distinctive task.

In this invention, the operator influenced control having three rangesof position for selecting which one of the three work feeding mechanismregulators shall be effective, also serves within certain of the rangesto influence additional regulation of the work feed mechanism. Thuswithin the first range of positions, the stitch length is set manuallyby turning the control dial and within the second range of positions,turning of the control dial influences the ratio of pattern cam movementto work feed movement.

With the above and additional objects and advantages in view as willhereinafter appear, this invention comprises the devices, combinationsand arrangements of parts hereinafter described and illustrated in theaccompanying drawings of a preferred embodiment in which:

FIG. 1 represents a front elevational view of the standard end portionof a sewing machine with the front escutcheon panel removed and porfionsof the machine frame broken away to expose the mechanism therein forminga part of this invention,

FIG. 2 is a vertical cross-sectional view taken substantially along line2-2 of FIG. 1 and showing the operator influenced control dial forselectively controlling which one of the three regulators will beconnected to the work feeding mechanism, but illustrating only two ofthe three regulators, i.e., the regulator for manual feed control andthe regulator for pattern cam control of the feed, 1

FIG. 3 is an elevational view of the control dial shown in FIG. 2 butwith the cam grooves in the exposed face eliminated so that the camgrooves in the hidden face which are shown in dashed lines will clearlybe indicated,

FIG. 4 is a vertical crosssectional view taken substantially along line4--4 of FIG. 1, a

FIG. 5 is a disassembled perspective view of the control dial and ofthose two work feed mechanism regulators which are illustrated in FIG.2, 1

FIG. 6 is a cross-sectional view of the assembled parts takensubstantially along line 6-6- of FIG. 5 and showing the pivot stud forthe cam control feed drive linkage together with the balancingadjustment,

FIG. 7 is a vertical cross-sectional view taken substantially along line77 of FIG. I and illustrating the buttonhole influencing cam mechanismand the regulator for controlling the work feeding mechanism duringbuttonholing operations,

FIG. 8 is an elevational view of the control dial of FIG. 3 but showingthe cam grooves in the exposed face thereof,

FIG. 9 is a vertical cross-sectional view taken substantially along line9-9 of FIG. 1 and illustrating the ratchet drive mechanism for thebuttonhole influencing cam, and

FIG. 10 is a disassembled perspective view of the buttonhole influencingcam mechanism and of the regulator for controlling the work feedingmechanism during buttonholing.

Illustrated in FIG. I are sufficient portions of a sewing machine frameclearly to indicate to those skilled in the an the disposition andgeneral arrangement of this invention. The sewing machine frame includesawork supporting bed 11, a standard 12 rising from the bed, and abracket 13 extending from the standard in overhanging relation to thebed. As shown in FIG. I, the front wall of the standard and bracket armis formed with an opening 15 bordered by a projecting rim 16 in which anescutcheon plate (not shown) may be seated. The drawings show theescutcheon plate removed to expose the mechanism. A top cover 17 for thebracket arm and a hinged lid 18 thereon are shown in cross section inFIG. 1.

A main shaft 20 is joumaled in the bracket arm and may be rotated by anyconventional means such as an electric motor or the like (not shown) todrive all of the mechanisms of the sewing machine. In the bracket arm,the main shaft may be provided with connections for operating a needlereciprocating mechanism and for driving pattern cams for influencingzigzag stitching and for providing cam control of the sewing machinework feed; these mechanisms may be of any known form, and therefore, arenot illustrated in detail in the accompanying drawings.

A bed shaft 21 joumaled beneath the work supporting bed 11 carries asprocket 22 engaged by a timing belt 23 which is driven by a sprocket 24on the main shaft 20. The bed shaft may be provided with connections fordriving a loop taker and with connections for driving a work feedingmechanism and since the loop taker, work feeding mechanism, and thedrives thereto may be of any conventional form they are not illustratedin the accompanying drawings. The buttonholing mechanism and work feedcontrols of this invention are shown in the accompanying drawings in aform which is particularly suitable for use with a sewing machine asillustrated in the above-referred U.S. Pat. No. 3,585,876, it beingunderstood that the buttonholing mechanism of this invention takes theplace of the buttonholing mechanism of the aforementioned United Statespatent. Similarly, the present invention is particularly suitable foruse with a sewing machine having a work feeding mechanism of the type ofwhich only portions are shown in U.S. Pat. No. 3,585,876, and this workfeed mechanism is described in greater detail in the copending U.S.application Ser. No. 810,951 filed Feb. 25, 1969, Szostak et al., nowU.S. Pat. No. 3,593,769, to which reference may be had.

The work feeding mechanism with which this invention is particularlysuitable for use includes a stitch length and direction regulating rockshaft 30 journaled in the sewing machine bed. One bushing, 31, for thefeed regulating work shaft is shown in FIG. 1 seated in a web 32 of thesewing machine bed. A bracket 33 is made fast on the feed regulatingrock shaft as by a setscrew 34 and this bracket is provided with meansfor accommodating engagement with any one of three separate linkages forregulating the sewing machine feed mechanism. The bracket 33 is formedwith a depending rock arm 35 having a chamfered extremity 36 adapted toreceive pattern cam influenced impulses to regulate the feed. Thebracket is also formed with a lateral rock arm 37 which is drilled andtapped as at 38 to accommodate a fastening screw 39 on which is carriedan eccentric collar 40 having a hexagonal flange 41. The eccentriccollar is adapted to cooperate with a manual feed regulating linkage. Atthe free extremity of the lateral rock arm 37, a shouldered pin 42 isfastened in place, which pin cooperates with a linkage forming a part ofthe buttonhole mechanism as will be described hereinbelow. The bracket33 is also formed with a projection 43 to which a spring 44 is attached.The spring is anchored in suitable manner on the sewing machine frameand serves to bias the feed regulating rock shaft 30 in acounterclockwise direction as viewed in FIG. 2 so as to urge the sewingmachine work feeding mechanism toward an extreme position in the reversedirection of feed of the work fabric.

Referring to FIGS. 2 through 6, the general features of the mechanism ofthis invention will now be described with particular emphasis upon themechanism for effecting manual control of the sewing machine workfeeding mechanism. A -shaped frame 50 is provided in which the mechanismof this invention is largely subassembled. The U"-shaped frame 50includes side limbs 51 and 52 and a base portion 53 joining the limbs.Mounting tabs 54 and 55, which extend outwardly from the side limbs 51and 52 respectively, accommodate fastening screws 56 by which U"-shapedframe is secured to mounting bosses 57 and 58 formed within the standardportion 12 of the sewing machine frame. As illustrated in FIGS. 1 and 5,an idler roller 59 for the bed shaft driving belt 23 may be carried bythe side limb 51 of the U"-shaped frame 50. The U-shaped frame 50 isalso provided with an auxiliary -shaped bracket 60 having side limbs 61and 62 and a base portion 63 which is secured to the base portion 53 ofthe U- shaped frame 50 by screws 64. It will be appreciated that theabove-described separate construction of the IF-shaped frame andauxiliary bracket is suitable for sheet metal construction of theseparts but that an integral frame member formed by molding or the likewould be equally suitable.

Joumaled between the side limbs 51 and 52 of the U"- shaped frame 50 isa stud shaft 70 which at its right-hand extremity is sustained in theside limb 52 of the frame by a shouldered screw 71, while at theleft-hand extremity the stud shaft is joumaled in a flanged bushing 72which bushing is held on the frame side limb 51 by a shouldered screw 74serving to sustain the stud shaft and the flanged bushing in place. Thisflanged bushing construction serves to provide a pivotal mount for anelement of the buttonhole mechanism drive which will be described laterin this specification.

Freely pivoted on the stud shaft 70 between the ends thereof is a quickreversing lever 75 for the sewing machine work feeding mechanism. Thequick reversing lever is formed with a finger grip 76 at one extremityand is formed at the other extremity with a laterally offset tang 77 towhich is attached a coil spring 78 anchored on a tab 79 struck out fromthe base portion 53 of the U-shaped frame 50.

To the right of the quick reversing lever 75 on the stud shaft 70, asviewed in FIGS. 1 and 5, is freely joumaled a cam member 90. Springclips 91, which are set into annular grooves 92 in the stud shaft 70,constrain the cam member 70 axially along the stud shaft. Preferably,the cam member is formed with a metallic hub 93 on which is molded theouter portion of the cam member which may be made of a synthetic plasticor the like. The cam member is preferably formed with a flutedperipheral flange 94 for operator engagement to turn the cam member. Onthe right-hand face, as viewed in FIGS. 1 and 5, the cam member isformed with a spiral cam groove 95 shown in FIG. 8. Other recesses 96 inthe righthand face of the cam member serve only to reduce the mass ofthe cam member.

The left-hand face of the cam member 90 is formed with a cam groove 97which, as illustrated in FIG. 3, includes three different portions. Atone extremity a portion 98 of the cam groove 97 is provided forregulating manually the stitch length of the work feeding mechanism andto this end the cam groove portion 98 is formed with sidewalls 99 and100 which gradually diverge. Adjoining the manual feed regulatingportion 98 of the cam groove is a second portion 101 of the cam groovewhich serves for positioning the parts for buttonholing operations; thisportion 101 takes the form of a radially outwardly bowed segment of thecam groove 97. At the extremity of the cam groove 97 is formed the thirdportion 102 which also extends radially outward and serves to positionthe parts for pattern cam control of the work feeding mechanism.

Referring now to FIGS. 2, 5, and 6, a stud shaft is carried between theside limbs 61 and 62 of the frame bracket 60. A spring clip 111 attachedto the stud shaft 110 outside the side limb 61 of the bracket is formedwith a projecting spring arm 112 which bears against the side limb 61frictionally to resist turning movement of the stud shaft. At the otherextremity, the stud shaft 110 protrudes through the side limb 62 of thebracket 60 and beyond the side limb 62 is fitted with a bushing 113 onwhich is pivotally mounted a cam follower lever 114 which is held on thebushing by a spring clip 115. At its free extremity, the cam followerlever 114 carries a laterally extending cam follower pin 1 16 whichtracks the cam groove 97 in the left-hand face of the cam member 90 asviewed in FIGS. 1 and 5. The cam follower lever 114 is formed with asubstantially radial slot 117 which accommodates the tang 77 on thequick reversing lever 75. Pivoted on a pin 1 18 on the cam followerlever 114 is a depending link 1 19 which is bifurcated as at 120 at thelower extremity to embrace the eccentric collar 40 which is secured onthe lateral rock arm 37 of the work feed controlling rock shaft 30. Aprojection 121 extending from the depending link 119 is engaged by aspring 122 which is anchored on one extremity 123 of a wire keeper 124which is attached by a screw 125 to the web 32 in the bed of the sewingmachine. The other extremity 126 of the wire keeper 124 serves toconstrain other parts of the sewing machine such as electrical wiringharness or the like away from interference with the mechanisms of thisinvention.

When the cam member 90 is turned to bring the cam follower 116 into thefirst portion 98 of the cam groove 97, the spring 122 will urge the camfollower against the inner sidewall 99 of the cam groove and as the dialis turned the cam follower will ride to varying distances'from thecenter of the cam member shifting the depending link 119 which willregulate the angular position of the feed regulating rock shaft 30accordingly, If at any time while the cam follower 116 is tracking thediverging walled portion 98 of the cam track 97, the quick reversinglever 75 is depressed, the cam follower will be elevated to the extentpermitted by the divergence of the outer wall 100 of the cam groove. Thewalls 99 and 100 of the cam groove are preferably constructed to dictatean approximately equal stitch length in reverse direction to the forwardstitch length at any particular setting of the cam member 90. The coilspring 78 on the quick reversing lever 75 is desirable to prevent thequick reversing lever from rattling during operation of the machine.

FIGS. 2 and 5 illustrate in addition to the mechanism for manuallyregulating the work feeding mechanism, the mechanism whereby the workfeed mechanism may be controlled automatically by a pattern cam toproduce repetitive stitch patterns in which the work feed varies in apredetermined manner. In FIG. 2 a fragment of the pattern cam shaft 130of the sewing machine is illustrated. This cam shaft is supported in thesewing machine bracket arm 13 and carries a worm wheel 131 in mesh witha worm (not shown) on the main shaft 20. A pattern cam 132 isillustrated on the pattern cam shaft 130 in a location usually consignedto control of the lateral position of the sewing machine needle and bywhich pattern cam controlled zigzag stitches are possible. Indicatedgenerally at 133 atop the pattern cam shaft 130 is an exchangeable camincluding a handle 134 which cam includes a pair of pattern cam flanges135 and 136 of which the upper carn flange 135 is adapted to influencethe work feeding mechanism by way of the linkage which will now bedescribed.

Indicated at 139 in the drawings is a pattern cam follower lever adaptedto track the cam flange portion 135. The cam follower 139 may beidentical in construction and arrangement to the pattern cam followerfor influencing the work feed mechanism in the U.S. Pat. No. 3,585,876,referred to hereinabove. The follower lever 139 is bifurcated at 140 andembraces a tang 141 on the upper extremity of a lever arm 142 and isformed at the opposite extremity with a slot 143 which embraces aneccentric portion 144 of a collar 145 which is secured to the stud shaft110 as by a pin 146. A spring clip 147 may be provided between the camfollower lever 139 and the lever arm 142 to remove lost motion betweenthese parts. Journaled on a concentric flange 148 formed on the collar145 is a bellcrank lever 149 having an upstanding arm 150 which isbifurcated and embraces a pin 151 in the lever arm 142. The bellcranklever also has a depending bellcrank arm 152 which at the lowerextremity carries a pivot pin 153 for a link 154. A lateral pin 155formed on the link 154 is selectively engageable with the depending rockarm 35 of the feed rock shaft bracket 32. Pivoted at 156 to the link 154is a control strap 157 which at its upper extremity carries a camfollower pin 158 which extends into tracking relationship with thespiral cam groove 95 in the cam member 90. The cam follower pin 158preferably projects through a slot 159 formed in a guard plate 160 whichis located against the cam member 90 and which serves to conceal the camgrooves from the view of an operator of the sewing machine. The link 154is preferably arranged in a guide slot 161 of a sheet metal bracket 162which is secured as by screw 163 beneath the sewing machine standard.

As the cam member 90 is turned counterclockwise beyond the positionillustrated in FIG. 2, the cam follower pin 158 in tracking the camgroove 95 will gradually raise the projection 155 on the link 154upwardly into engagement with the depending rock arm 35. At the sametime the cam follower 116 in tracking the third portion 102 of the camgroove 97 in the left-hand face of the cam member 90, as viewed in FIGS.2 and 5, will first slightly depress the depending link 119 of themanual feed controlling linkage to move the depending rock arm 35slightly in a clockwise direction as viewed in FIG. 2 to insure that thepin 155 will move into engagement with the right-hand side of the rockarm 35 as viewed in FIG. 2. The cam follower 116 in tracking theremainder of the cam portion 102 of the cam groove 97 will move thedepending link upwardly to such an extent that the bifurcated end 120 ofthe link will shift upwardly completely out of the range of possiblecontact with the eccentric collar 40, thus freeing the work feedregulating rock shaft 30 for influence solely by the pattern cam 135.

For balancing the pattern cam controlled influence of the work feedingmechanism so that the actual position of zero stitch length of feedmotion may be regulated relatively to the pattern cam track, means areprovided for shifting the angular relationship of the bellcrank lever149 with respect to the lever arm 142. This balancing regulation isaccomplished by means of a lever arm 170 which is fixed to the collar onthe stud shaft 110. A pivot pin 171 connects the lever arm to a link 172which extends upwardly and is pivotally connected in turn by a pin 173to a crank arm 174 which is secured as by a clamp 175 to a dial segment176. The dial segment 176 is joumaled in a bearing aperture 177 formedin an upstanding arm 178 of a bracket 179 which is secured by screws 180to the machine frame. The bracket arm 178 of the bracket 179 may beformed with an out-tumed tang 181 for cooperation adjacent the peripheryof the dial segment 176 to provide an indication of the balance'settingof this mechanism.

Pivotally mounted in another bearing aperture 185 in the upstandingbracket arm 178 is a dial segment 186 formed with a radial finger griptab 187 and with a projecting nose 188 arranged for engagement with thelever arm 142. The dial segment 186 when turned in a clockwise directionas viewed in FIG. 5, serves to shift the cam follower lever 139 so as toremove the cam follower from tracking relation with the pattern cam.This cam follower removal provision is useful when it is desired toexchange pattern cams. A pin 189 projecting from the dial segment 186accommodates one extremity of a coil spring 190 of which the otherextremity is anchored in the sewing machine frame so as to bias the dialsegment 186 into a retracted inoperative position.

Referring now to FIGS. 7 to 10, the mechanism will be described by whicha closed tack of stitches, such as a buttonhole, may be madeautomatically with this invention. In FIG. 10 is illustrated a cammember 200 which regulates the automatic formation of buttonholes by thesewing machine and which is freely rotatable on the stud shaft 70 on theleft-hand side of the quick reversing lever 75. The cam member 200 maypreferably be constructed with a metallic hub portion 201 and with amolded plastic outer portion 202 enveloping the hub portion. The cammember 200 is formed with a peripheral flange 203 which is serated forbetter grip by a sewing machine operator, and as shown in FIG. 10 thecam member is formed in the right-hand face with a wide cam track 205 ofwhich only the radially innermost wall 206 provides the active camsurface. Tracking the inner wall206 of the cam track 205 is a followerpin 207 secured to one arm 208 of a three-armed lever 209 which isfulcrumed on a shouldered pin 210 secured in a tab 211 formed on theauxiliary bracket 60 in which the feed control unit is subassembled. Anupstanding and forwardly extending lever arm 212 of the three-armedlever 209 has fixed at its free extremity a collar 213 formed with abore 214 and provided with a setscrew 215 which can be threaded into thebore. A pivot pin 216 fonned with an eccentric shoulder 217 and with ahexagonal head 218 is accommodated in the collar bore 214 and with theuse of the setscrew 215 the angular position of the eccentric shouldermay be selectively determined. A depending link 219 is joumaled on theeccentric shoulder 217 and the lower extremity of the depending link 219is formed with a lateral abutment surface 220 and with a guide finger221 depending beneath the abutment surface 220 and extending adjacentthe shouldered pin 42 which is fixed in the rock arm 37 of the bracket33 on the feed controlling rock shaft 30. A coil spring 225 is attachedat one extremity to the depending arm 208 of the three-armed lever 209and is secured at the other extremity to a fastening aperture 226 alongthe depending link 219 so as to bias the lateral abutment surface 220 ofthe link 219 toward a position asshown in FIG. 7 in engagement with theshouldered pin 42. A bellcrank "lever 230 fulcrumed on a shoulderedscrew 231 threaded into the side limb 52 of the frame 50, is formed witha depending arm 232 carrying a lateral pin 233 which extends alongsidethe depending link 219, an upper arm 234 of the bellcrank 230 carries acam follower pin 235 which extends through an aperture 236 in the guardplate 160 and tracks a cam groove 237 formed in the right-hand face ofthe cam member 90. As shown in FIG. 8, the cam groove 237 may be formedradially inwardly of the spiral cam groove 95 in the right-hand face ofthe cam member 90. The cam member 90, therefore, determines which of thethree linkages will be operatively connected to regulate the work feedmechanism controlling rock shaft 30. As previously described, the cammember 90 moves the lever I 19 into position for manual control of thework feeding mechanism during one range of position of the cam member90, and in another range of positions influences connection of the link154 with the work feed controlling rock shaft 30. As describedimmediately above, in a third range of positions of the cam member 90,the cam follower pin 235 will be urged radially outward into theposition as illustrated in FIG. 8 so as to turn the bellcrank 230thereof counterclockwise as viewed in FIG. 7, moving the lateral pin 233to the right and allowing the coil spring 225 to draw the abutment 220into engagement with the pin 42 on the rock arm 37. When the cam member90 is in the position illustrated in FIG. 8, the manual feed controllinglink 119 will be elevated by the cam groove portion 101 of the camgroove 97 and will be out of engagement with the work feed controllingmechanism. Similarly, when the buttonholing control link 219 is ineffective feed regulating position as shown in FIG. 7, the pattern camcontrolling linkage will be dropped out of effective position as shownin FIG. 2 by the spiral cam groove 95.

A tab 240 struck out from the upper arm 234 of the bellcrank 230provides for attachment of a coil spring 241 anchored at the otherextremity in a finger 242 formed on a spring clip 243 which is securedby screw 244 to the right side limb 52 of the frame 50. A bent finger245 of the spring clip 243 projects through an opening 246 in the frame50 and bears against the right-hand side face of the cam member 90 toprovide a frictional resistance to the turning movement of the cammember 90 and to deter accidental angular shift of this cam member.

In the position of parts as shown in the drawings, therefore, in whichthe abutment 220 on the depending link 219 of the buttonholing mechanismis shifted into engagement with the pin 42, the follower pin 207 of thethree-armed lever 209 in tracking the inner cam wheel 206 on the cammember 200 will influence the work feed mechanism of the sewing machine.The cam surface 206 is preferably formed so as to provide for areversal. of the feed direction upon movement of the cam member 200 ineach quadrant of a complete turn of the cam member 200. In order toproduce a buttonhole, only two changes of feed control are necessary,and therefore, a buttonhole may be produced with only one-halfrevolution of the cam member 200 or conversely, two buttonholes may beproduced during one complete revolution of the cam member 200. The camwheel 206 is preferably designed so as to provide movement of thethree-armed [ever 209 sufficient to influence only a very short stitchlength of the work feeding mechanism in each direction of work travelthrough the machine. The eccentric shoulder 217 on the pivot pin for thedepending link 219 is preferably formed with a very slight eccentricityso that a very accurate adjustment of the balancing between the forwardand the reverse direction of work feeding can be attained. This veryaccurate stitch balancing ability of the present invention duringbuttonholing is advantageous because very slight differences in stitchlength are readily apparent in a buttonhole because the opposite sidesare stitched closely adjacent each other and the comparison is evident.

A third arm 250 is formed on the three-armed lever 209 and extendsrearwardly and upwardly as shown in the drawings and carries a pivot pin251 which engages a slot 252 formed in a crank arm 253 fast on a rockshaft 254 which is journaled in spaced upstanding arms 255 and 256 ofthe bracket 1179. At

the other extremity the rock shaft 254 carries a rock arm 257 whichprovides a connection for the buttonholing mechanism with the needlejogging mechanism of the sewing machine so that during buttonholeformation the field of zigzag stitching of the sewing machine may beshifted from left to right at one end of a buttonhole and from right toleft at the opposite end of the buttonhole. The mechanism which isoperated by the rock arm 257 is not illustrated in the accompanyingdrawings nor will it be described herein because this mechanism may beof any known conventional form, for instance, as described in detail inthe US. patent application Ser. No. 739,05l which has been referred toearlier in this specification. A coil spring 260 may be provided betweenthe bracket 60 and the third arm 250 of the three-armed lever 209 tobias the cam follower pin 207 against the cam wall 206 of the cam member200.

Referring to FIGS. 1, 9, and 10 the means will now be described by whichthe cam member 200 may be turned in quarter revolution increments duringoperation of the sewing machine to produce buttonhole-shaped tacks ofstitches. Fast on the sewing machine main shaft 20 adjacent to thesprocket 24 is an eccentric 270 which is embraced by a strap 271 towhich a sheet metal extension 272 is secured by a screw 273. Pivoted bya pin 274 to the extension 272 is a rock lever 275 which is joumaled onthe flanged bushing 72 which was previously described. Fulcrumed on apin 276 secured in an upstanding arm 277 of the rock lever 275 is a pawllever 278 formed with a ratchet engaging finger 279 and with a tail 280to which a coil spring 281 is engaged. The coil spring may be anchoredin the extremity of the lever arm 277 for biasing the pawl lever to urgethe pawl finger 279 toward a ratchet wheel 282 which is formed as a partof the left-hand face of the cam member 200 as viewed in FIG. 10. Asbest shown in FIG. 9, the ratchet wheel 282 on the cam member 200 ifformed with four substantially evenly spaced ratchet toothed portions283. The ratchet toothed quadrants are separated alternately by blankportions 284 having a diameter substantially equal to that of the tipsof the ratchet teeth and blank portions 285 formed at least partly witha recess 286 substantially equal to the root diameter of the ratchetteeth. Each of the blank portions 284 and 285 are of a width whichexceeds the stroke of the pawl finger 292 in response to the driveimpulses of the eccentric 270.

The left-hand face of the cam member 200, taken as viewed in FIG. 1, ispreferably provided with a guard plate 290 to screen the face of the cammember 200 from the view of an operator of the sewing machine. The guardplate 290 is formed with an aperture 291, as shown in FIG. 9,substantially in register with an aperture 292 in the left side limb 51of the frame 50. A spring member 293 secured to the frame 50 by afastening screw 294 is formed with a bent finger 295 which extendsthrough the apertures 29] and 292 and bears against the face of theratchet wheel 282. The face of the ratchet wheel 282 is provided withdepressions 296 arranged for cooperation with the spring finger 295 toprovide a definite frictional resistance to turning movement of the cammember 200 in specific angular locations as the cam member 200 is turnedthroughout a revolution. It will be noticed in FIG. 9 that thedepressions 296 are arranged substantially in four quadrants and that inevery other quadrant there is provided a single depression 296 while inalternate quadrants a pair of depressions are provided. The first ofeach pair of depressions, when engaged by the finger 295 locates the cammember 200 in a position as shown in FIG. 9 with the pawl finger workingin a recess 286 of a blank portion 285 on the ratchet wheel whichposition corresponds to a beginning or an end of a buttonhole. When themachine operator wishes to begin a buttonhole she manually turns the cammember to carry the spring finger 295 into the second of the pair ofdepressions 296 which will engage the pawl with the first ratchet toothof succeeding toothed portion 283 and initiate the formation of one endof a buttonhole. The subsequent operation of the sewing machine will byway of the eccentric 270 cause the cam member 200 to move one-quarterturn during which time the cam surface 206 will shift the three-armedlever 209 gradually and during this shift will change the feed directionand shift the field of zigzag stitching from one side to the other thusproducing one end of a round end buttonhole. The pawl finger 279 willthen reach the succeeding blank portion 284 of the ratchet wheel, andthe three-armed lever 209 will remain in fixed position while the sewingmachine will continue to operate forming one side of the buttonhole foras long as the machine operator desires. When the pawl finger 279reaches a plain blank portion 284 of the ratchet wheel 282, the springfinger 295 will be located adjacent to but not yet seated in a singledepression 296, and the mechanism will rest in a position for formationof one side of a buttonhole. After one side of the buttonhole has beenstitched to the extent deemed necessary by the operator, she simplynudges the cam member 200 until the spring finger 295 drops into thenext adjacent single depression 296. This will shift the pawl fingerinto cooperation with the next toothed segment 283 and the ratchetdevice will again drive the cam member 200 to form the second end of thebuttonhole and leave the controls set for sewing the second side of thebuttonhole. The ratchet will drive the spring finger 295 into the firstof the next pair of depressions which is the off or stored position ofthe device,

In the off or stored position, as illustrated in FIG. 9, the ratchetfinger 279 being in a recess 286 will be urged to a lesser degree by thespring 281 and wear of the pawl finger will be minimized.

To set the machine for buttonholing, the operator, therefore, need onlyturn the cam member 90 to the position illustrated in the drawings inwhich the depending link 219 of the buttonholing mechanism linkages isin operative position in engagement with the shouldered pin 47 and alsothe operator should make a proper setting of the bight of zigzagging ofthe needle jogging mechanism of the sewing machine for buttonholing.Buttonholing can then be initiated simply by manually turning the cammember 200 for a sufficient distance as to bring the spring finger 295into engagement with the next depression 296 as explained above.

Having thus set forth the nature of this invention, what is claimedherein is:

1. in a sewing machine having a work feeding mechanism including a meansresponsive to the angular position of a feed regulating shaft forvarying the magnitude and direction of feed, a control device for saidwork feeding mechanism comprising, a first linkage operatively connectedto a manually influenced adjusting means in said sewing machine, asecond linkage operatively connected to a pattern cam follower in saidsewing machine, a third linkage operatively connected to a buttonholingunit in said sewing machine, an operator influenced selector elementshiftably supported in said sewing machine, and means associated withsaid selector element for effecting operational engagement of anyselected one of said linkages with said feed regulating shaft.

2. A control device for a sewing machine work feeding mechanism as setforth in claim 1 in which each of said linkages includes a separatemanually adjustable means for balancing the forward and reversedirections of feed.

3. A control device for a sewing machine work feeding mechanism as setforth in claim 1 in which a bracket is secured to said feed regulatingshaft and carries three separate connection elements, and in which saidmeans associated with said selector element for effecting operationalengagement of any selected one of said linkages with said feedregulating shaft includes cam means for shifting said linkagesselectively into engagement each with a respective one of saidconnection elements on said bracket.

4. A control device for a sewing machine as set forth in claim 1 inwhich said manually influenced adjusting means for said first linkage isformed as a part of and shiftable with said operator influenced selectorelement.

5. In a sewing machine having a work feeding mechanism including a meansresponsive to the angular position of a feed regulating shaft forvarying the magnitude and direction of feed, a control device for saidwork eeding mechanism comprising a supporting frame adapted to besecured in said sewing machine, three separate linkages carried by saidframe, an axle joumaled in said frame, a manually rotatable cam diskjoumaled on said axle, three separate cam means formed in said cam disk,follower means on each of said three separate linkages each tracking arespective one of said three separate cam means for shifting saidlinkages selectively into operative engagement with said feed regulatingshaft, said cam means tracked by a first of said separate linkagesproviding for manual influence of magnitude and direction of feed whilesaid first linkage is positioned in operative engagement with said feedregulating shaft, a second of said separate linkages including patterncam follower means for sewing decorative stitches with repetitive workfeed variations, an intermittently driven buttonholing control unitjoumaled on said axle, and means on a third of said separate linkagesresponsive to said buttonholing control unit for influencing regulationof said work feeding mechanism.

1. In a sewing machine having a work feeding mechanism including a meansresponsive to the angular position of a feed regulating shaft forvarying the magnitude and direction of feed, a control device for saidwork feeding mechanism comprising, a first linkage operatively connectedto a manually influenced adjusting means in said sewing machine, asecond linkage operatively connected to a pattern cam follower in saidsewing machine, a third linkage operatively connected to a buttonholingunit in said sewing machine, an operator influenced selector elementshiftably supported in said sewing machine, and means associated withsaid selector element for effecting operational engagement of anyselected one of said linkages with said feed regulating shaft.
 2. Acontrol device for a sewing machine work feeding mechanism as set forthin claim 1 in which each of said linkages includes a separate manuallyadjustable means for balancing the forward and reverse directions offeed.
 3. A control device for a sewing machine work feeding mechanism asset forth in claim 1 in which a bracket is secured to said feedregulating shaft and carries three separate connection elements, and inwhich said means associated with said selector element for effectingoperational engagement of any selected one of said linkages with saidfeed regulating shaft includes cam means for shifting said linkagesselectively into engagement each with a respective one of saidconnection elements on said bracket.
 4. A control device for a sewingmachine as set forth in claim 1 in which said manually influencedadjusting means for said first linkage is formed as a part of andshiftable with said operator influenced selector element.
 5. In a sewingmachine having a work feeding mechanism including a means responsive tothe angular position of a feed regulating shaft for varying themagnitude and direction of feed, a control device for said work feedingmechanism comprising a supporting frame adapted to be secured in saidsewing machine, three separate linkages carried by said frame, an axlejournaled in said frame, a manually rotatable cam disk journaled on saidaxle, three separate cam means formed in said cam disk, follower meanson each of said three separate linkages each tracking a respective oneof said three separate cam means for shifting said linkages selectivelyinto operative engagement with said feed regulating shaft, said cammeans tracked by a first of said separate linkages providing for manualinfluence of magnitude and direction of feed whiLe said first linkage ispositioned in operative engagement with said feed regulating shaft, asecond of said separate linkages including pattern cam follower meansfor sewing decorative stitches with repetitive work feed variations, anintermittently driven buttonholing control unit journaled on said axle,and means on a third of said separate linkages responsive to saidbuttonholing control unit for influencing regulation of said workfeeding mechanism.